Tube former and method of making same



June 14, 1960 c. E. MONSEES EI'AL 2,940,408

TUBE FORMER AND METHOD 0F MAKING SAME Filed Jan. 21, 1959 Haze Ls Ii Caoper ATTORNEYS IN VENT 0R5 (Ya/ad? E 110125665 United States Patent TUBE FORMER AND METHOD OF MAKING SAlVlE Claude E. Monsees and Francis H. Cooper, Durham,

N.C., assignors to Sperry Rand Corporation, Wilmington, Del., a corporation of Delaware Filed Jan. 21, 1959, Ser. No. 788,185

7 Claims. (Cl. 113-116) This invention relates to tube formers, and particularly to tube formers adapted to guide and direct a continuous web of bag-forming material to and through the interior of a cylindrical former to thereby form the flat web into a cylindrical tube with overlapping edges and without employing an internal mandrel.

In brief, the invention comprises a novel tube former of the type wherein a hollow cylindrical member is provided with an upper edge curving generally obliquely across the cylinder and a generally conical collar or guide portion joined to the cylinder at the upper edge thereof. A free edge of the collar portion defines a straight line transverse to the web to be guided thereby and the collar is curved into generally conical shape and intersects the cylindrical portion at its upper edge to thereby guide a flat web into cylindrical configuration against the interior surface of the cylindrical portion wherefrom it may be drawn downwardly through the former and will emerge as a cylinder which may be sealed and cut into bags as desired. The particular novelty resides in such a tube former wherein the collar portion and the cylindrical portion are formed of an integral and continuous sheet of material, preferably metal, whereby the web-guiding surfaces of. the two portions are integral and continuous.

The tube former of the present invention is formed from a flat sheet of metal by providing a groove in one surface thereof, the groove being curved according to an equation, to be described, whereupon the sheet may thereafter be folded along the groove into the finished form described above. The invention herein comprises the tube former of novel construction, a method of forming the same, and a novel blank from which the tube former may be constructed.

It is therefore an object of this invention to provide a novel form of tube former having means to guide a continuous web of flexible material to the interior of a hollow cylindrical former to form the web into a cylinder without the use of an interior mandrel and wherein the guide surfaces are so formed and constructed that no unequal or excessive strains are placed on any portions of the bag-forming material.

Another object of this invention is to provide a tube former of the type set forth wherein the guiding surfaces of a collar portion and a cylindrical portion are continuous and integral and wherein the distance along said surfaces, measured in the direction of movement of a web guided thereby, are all exactly equal.

Still another object of this invention is to provide a novel tube former structure by which the previous objects are attained.

A further object is to provide a novel method of making a tube former from a single integral sheet of material.

A still further object of this invention is to provide a novel structure and method for a tube former whereby a former of any desired size may be produced.

An additional object of the invention is to provide a novel sheet metal blank for the formation of a tube former as described.

Other objects and advantages will become apparent to those skilled in the art as this description proceeds with reference to the accompanying drawings, wherein:

Fig. 1 is a top plan view of .a novel tube former embodying the present invention;

Fig. 2 is a'front elevational view of the tube former of Fig. 1;

Fig. 3 is a side elevational view of the tube former of Fig. 1;

Fig. 4 is an enlarged fragmentary sectional view taken substantially along the line 4-4 of Fig. 2;

Fig. 5 is a plan view of a blank from which the tube former of Figs. 1 to 3is fabricated; and

Fig. 6 is an enlarged fragmentary sectional view taken substantially along the line 6-6 of Fig. 5.

The tube former shown in Figs. 1, 2 and 3 is designed to guide a web 2 (see dotted lines of Figs. 2 and 3) of flexible bag-forming sheet material into a cylindrical shape with overlapping longitudinal edges and without the employment of an internal mandrel or the like. The tube former comprises a hollow cylindrical portion 4 having overlapping but slightly radially spaced edge portions 6 and 8 and a guiding or, collar portion 10. The

portion 10 is referred to hereinafter as a collar portion for convenience, in view of its resemblance to the collar of certain garments. The collar portion 10 is straight in a transverse direction along its edge 12 and is progressively curved into a generally conical shape, as shown, to where it intersects the upper edge 14 of the cylindrical portion 4. The collar portion 10 is not of trueconical configuration since the degree and direction of curvature varies progressively to form a compound curve. ever, for purposes of convenience, the shape of the collar portionwill hereinafter be referred to as generally coni-,; The uppermost surfacev of the collar portion v10 cal. constitutes a guide-surface along which a face of the Web 2 slides andis guided toward the edge 14. ,At the edge 14 the web 2 folds inwardly and downwardly and follows the inner surface of the cylindrical portion 4 to emerge therebelow, at 16, in the form of a tube or cylinder having overlapping longitudinal edges 18. The downwardly extending tubular portion 16 of the web 2 may be drawn downwardly through the cylindrical portion 4 in a continuous or in a step-by-step manner and the collar portion 10 guides the web 2 unerringly and smoothly to and over the edge 14.

For a device of the type described above to operate satisfactorily and successfully, it is essential that the distance along the guiding surfaces of the collar 10 and cylinder 14, measured in the direction of movement thereover of all portions of the web 2, be exactly equal from the edge 12 to the lowermost terminus of the edge 14. Thus, all transverse portions of the web 2 must be drawn at the same speed, with the same tension, and must at all times be in sliding contact with the guiding surfaces of the collar 10 and cylindrical portion 4. If there were a projection on the edge 14 or inequality in the lengths of the paths described, the web 2 would buckle or fold and would become torn and the apparatus would not function satisfactorily.

To insure equality of all of the paths of movement of portions of the web 2, as described above, the cylindrical portion 4 and the collar portion 10 are formed from a single integral sheet of material, preferably metal, and the guiding surfaces thereof are defined by the original integral and uninterrupted surface of the sheet from which the tube former is constructed.

Fig. 5 shows a' flat rectangular blank 26 or sheet Patented June 14, 1960 met- 1} having a curved groove 22 extending-thereacross formed as a rather wide angled V-groove, preferably-jot I I 7 the-order of about 150 included angle. Theiblank20 25 It will be evident that, with the above equation, a tube fold and while the blankis being-thus folded the portion forcibly assume the configuration of the guidingfcollar as described, the flange 24 is preferably formed bybend-i 1 ing along the dotted line 23; After folding the'blank 20 to the desired shape, the groove 22 is filled with 'a' t maybe and preferably is formed of stainless steel and '22-'which maybe done by flowing molten silver fsolder' metallic materials,'if desired. 7

of the portions26 and 28 and their total is exactly that ;The edge 14 thus defines the intersection of verticalcylinder '4 and an imaginary horizontal cylinder transverse t to; the cylinder 4-at 34, The horizontal imaginary cyl- 7o extends transverselyacross the"diametricallyopposite edge ofthe cylinder;4. The fangle B: is shown as'the I angle between the collar portion 10and1theicylinder: 4"

I 7 2,940,408 t V 3 angle at which the web ofmateriaI- Z approaches the'axis' of the cylindrical portion of the tube former.

and terminating at the edges of the blank 20 closely 7 adjacent one end thereof. Obviously, however,'the lower The portion 28 of the" blank 20 is a flat'develo'pment edge of the blank 29 could be lower than shown, reof the cylindrical portion 4 and the apex of groove 22 sulting only in a longer: cylindrical portion 4. x The 5 is a fiat development of the edge 14. The equation govbroken line23 indicates a line along which"theblank'20 eming the curvature of the groove 22 is:

In theab'ove 'equat'ionthe quantity d isfthe desired is folded to-provid e the flange 24 vwhich'in turn teri internal diameteno'f'the'cylindrical portion. 4 and the minates in and defines the edge 12 previously referred A toindes'cribing the finished tube-former.- Asis apparent, angle B is the desired approach aiigleffor the web, dethe curved groove 22 is bowed upwardly as seen in Fig. 5 scribed above in connection witlr'Fig. 3. The v'ariables x 'ancldivide's the blank 20'into two ortions. The portion n y are the pv tion ecp n e variables m 26, on thetconvex side of groove 22, is the material. ured along the edges'of'the blank'20asindicatedin Fig. from which thecollar '10 is formed, -whei'eas'theiportion 5. It is to be noted that the angle B is the angle be- 28 on the concave side of-tlie groove 22, is the'portion tween the collar portion 1 0 and the cylindrical portion from"which the' cylindrical portion 4is formedf The 4 in the axial plane of'p'ortion'4 containing that poi'nt groove 22 is of genei'alIy V-sh ape cross-section (see of edge l4 wherein' y has itsgreatestvalue. Thevalues Fig.6) and is 'formed'to extend from one-half to two- .6522 and 5.22 are empirical constants'expressing the relationship'between angle Band the angle q) (Fig; 3); The sine of 5 appears in the above equation but 4: --is expressed in terms of B and the empirical'constants.

thirds of the way through the thickness of the slieetofm'ater'ial'constit-uting the'blank 20. The groove 22 is former-may be designed and constructed to any desired size and wherein the web approaches thetube former at substantially any desired angle. The groove 22, formed in the blank 20,'may be described as beingbowed upwardly but may also be described as curving continuously in the same directionsince' there are no reverse-curved e portions. t i 10 as'described and shown in connection with Figs'. 1 a The provision of the groove 22 renders it relatively to--3-.' Before the blank of Fig 5-is"-folde'd' and formed e sy o fold the blank 20 t mannerdescribed along an accuratelycontrolled line whereby the" desired finished tube-formenmayjbe produced with certainty and v 4 to a high degree of accuracy. 7 reinforcing material, bonded to the mateirial' of the blank W ile a single sp ifi e b nt f th i vention whereby to define a rigid and firm tube-former. Fjg 4 is shown and described' herein, it is 'tobe understood shows, at' 30, the reinforcing efi L 5 hg lg k zo that other modifications and;departures from the specific of Fig. 5 is folded along the apex'of-the groove22 in such a manner that the groove is on the inside of the thc filler materialao is metal deposited in. the"-gro o've" pp claims- We claim: orf-thelike into the groove wherebyit'isfsecurely -bonded" to'the metal of the tube former; However,--this tube esheetof, metal Q p 111%? steps O groove former may be constructed of other metals or'ev'en'noncompletely across ne f ce of said sh y i s By reference'to Fig. 4 it will be seen thatfthe edge' ld," Sheet along Said groove as a iold linewith sflidlgrofive which defines the intersection of' the surfaces of collar 1 6 inside of i f line,"and Simultaneously forr'ning the portion of said sheet on the'concave side of said groove to define a cylinder.

2. The method of claim lwh'erein said groove is of t substantially V-shape in section and extends fiom oneof" the blank 20. Therefore, the conditions 7 requisite t or Y- u l Sheet for the equality of lengths of the paths previously re- T methQd of claim 1 wherein i 'igrtoover 'iS ferred to are present and the edge'14' is asrnooth unformed as P d groove having an'illchldred anglev interruptededge defined bya continuous integral surface. of aPP Y 7 By reference now to Fig. 3, the internal'diameter 'of The method 0f 613ml"1 h 'Saia groove the cylindrical portion 4 is identified as d and the-laterally formed to follow the curve defined by theiequationz 10 'and cylindrical portion 4, is'a continuous, smooth and'integ'ral surface of the original blank and the ar eas of the'guiding surfaces are exactly'th same as'the areas horizontal projection of the edge 14 is a circular arc of 5 wherein y is the distance of said curve from a reference radius R 'havlng 1ts center at 32 (an imaginarypoint). I 7 axis, x is the distance alongsaid axis, d isthe desired inside diameter of said cylinder, and Bis the desired angle tothe' cylinder 4 having its axislat 32 and being tan'gent e of y 'is greatest.

inder' is tangent to the cylinder 4 only at point 34'and of: filling 'said groove, on the inside of the fold, with metal and fnsingsaid metal to saidsheet. I

disclosure may beresortedto within the scope of the- 1. The method of 'forming a tube former from a single curving continuously-in the same direction; folding said I between said folded portions at the point where the value 5. The method of claim; lyincluding the ifurthe'r' step 6. A blank for a tube for merco mprising a rectanguv V lar sheet of me ta'l, a groove extending-transversely across at the uppermostextremity of the edge 14 and isthe one face of said sheetbut bowed'toward onefend of said sheet, said groove being of V-shape in section and extending from one-half to two-thirds of the way through said sheet.

7. A blank as defined in claim 6 wherein said groove is bowe d to follow the curve:

1 sin (.6522B5.22)

References Cited in the file of this patent UNITED STATES PATENTS Fitch June 2, 1942 McKee Nov. 25, 1947 Klym July 15, 1952 Henchert Dec. 16, 1952 Iarund Apr. 29, 1958 Arnit Ian. 20, 1959 Leasure Aug. 18, 1959 

